In recent years, the proliferation of wireless LAN devices has enable computer peripheral devices, such as a printer for instance, to be connected via air wires. Various wireless LAN methods including the IEEE 802.11 standard, the Bluetooth standards and similar ones are becoming well known, pushing the IEEE 802.11 standard wireless LAN method to become a de facto global standard.
In accordance with the popularization of personal computers including IEEE 802.11 standard wireless LAN devices, peripheral devices such as printers, also including IEEE 802.11 standard wireless LAN device, are increasingly used.
The wireless LAN device communicating by an IEEE802.11b standard, which is one of the IEEE 802.11 standards, comprise a star-connection mode called infrastructure mode and a one-to-one connection mode called ad hoc mode that enable communication with another computer or the like, using either one of these modes. In the infrastructure mode, the MAC address of an access point at the center of the star connection is generally used as an initial group ID.
Further, in the ad hoc mode, although communication is standardized on the premise of the use of SSID, communication is frequently performed by using an IP address instead of the SSID of the wireless LAN device. In this case, the IP address initial value of the wireless LAN device is set to “0:0:0:0” or the like, and the IP address of the other wireless LAN device is set to “0:0:0:1” or the like. Then, the wireless LAN devices search for respective IP addresses and perform communication.
Since the “MAC address” referred to as an initial ID of the infrastructure mode is a device unique number, thus the ID of a wireless LAN device placed in an arbitrary room does not overlap the ID of another wireless LAN device placed in a neighboring house or office. Accordingly, the wireless LAN device placed in an arbitrary room is does not connect to a personal computer or peripheral device in a neighboring house or office.
In Japan, a maximum of 4 channels can be ensured as non-overlapped frequency channels for IEEE 802.11b wireless LAN devices. Among these 4 channels, a channel where interference wave is reduced as much as possible is used instead of a channel used by another user.
Further, in another known system, a frequency channel is determined from a serial number for the purpose of allocation of station (Japanese Patent Application Laid-Open No. 2000-059388).
When a peripheral device is connected to a computer via a wireless LAN, two types of problems occur regarding security and peripheral device user interface occur.
In some cases, the initial group ID of a wireless LAN card or access point is a banal initial value such as “Anyone”. Further, in many cases, no encryption key is set. Accordingly, the wireless LAN may be erroneously connected to a wireless LAN device newly placed in a neighboring house or office. In such case, data can be viewed from both wireless LANs.
In the infrastructure mode, a wireless LAN device can receive a beacon outputted from an access point placed in a neighboring house or office. If no encryption key is set at the access point, as a group ID can be obtained, and eavesdropping becomes possible by receiving the beacon from the other access point.
Further, in the ad hoc mode, the initial IP address value is a common one in many cases. This creates a serious security problem in communication.
Further, in the case of IEEE 802.11b wireless LAN device, since the number of selectable channels is small, there is a high probability to observe an overlap of selected frequency channels between a wireless LAN device and neighboring wireless LAN devices. Accordingly, the IDs and/or initial IP addresses can be the same with high probability, even when determining a frequency channel from a serial number, thus the probability of erroneous connection with a network in a neighboring house or office increases.
More particularly, in a computer peripheral device such as a printer, the setting user interface is often poor. Accordingly, before the execution of real radio communication, a radio communication to the computer is performed by using a simple initial ID or IP address, so that a new ID or IP address for the peripheral device is set using the computer's rich user interface. Otherwise, the computer is cable-connected to the peripheral device, to set a new ID or IP address for the peripheral device using the computer and executing an initial setting program.
However, security problems still occur in both cases, wherein the setting phase is operated via a cable or radio communication, since the setting operation is very complicated.